~anthropic/claude-sonnet-latest → A (7:3)

Side A fixes a real correctness bug (implicit feed cutoff using timestamps that can collide or move backwards) with a principled ingest-order anchor, adds a room field to prevent private-content leakage, and backs this with substantial multi-user permission integration tests. Side B is a pure refactor (splitting forum.rs into submodules) plus an unrelated dev tooling script, providing organizational value but no functional fix or new guarantees, and its diff even reintroduces some inline duplication it had previously factored out.